With growing of technologies, lot types of display apparatus are widely used in homes, schools and business occasions (e.g. displays, monitors and projectors) for displaying images or videos. In recent years, the technologies grow day by day, so the user demands of high-resolution and high-pixel also increase, among which the High Definition Television (hereinafter HDTV) is the most popular product in the modern society for industry and user.
Generally, a display apparatus has a native color gamut according to the characteristics of the panel and the display module after being fabricated. The display apparatus has to be adjusted in order to match the standard of color gamut of HDTV and have the same color performance with other display apparatuses, which means that the display color gamut of the display apparatus has to be adjusted from the native color gamut to the standard color gamut of HDTV (i.e. ITU-R Recommendation BT. 709 or Rec. 709). Please refer to FIG. 1. FIG. 1 schematically illustrates the color gamut of a conventional display apparatus of prior art. The region surrounded by the points 101, 102 and 103 is CIE 1931 standard color gamut defined by the Commission internationale de I′éclairage (CIE). Since the points 101, 102 and 103 are drawn in CIE x, y color space, the region surrounded by the points 101, 102 and 103 is CIE 1931 standard color gamut in CIE x, y color space, among which the point 101 is corresponding to a monochromatic light with 700 nm wavelength (i.e. red light), the point 102 is corresponding to a monochromatic light with 520 nm wavelength (i.e. green light), and the point 103 is corresponding to a monochromatic light with 380 nm wavelength (i.e. blue light).
As described above, after being fabricated, the display apparatus has a native color gamut, which is drawn as a triangular region surrounded by the points 201, 202 and 203. The points 201, 202 and 203 are corresponding to the coordinates of the red light, the green light and the blue light of the display apparatus, respectively. In other words, all the color coordinates of the colors displayed by the display apparatus are located in the native color gamut, so that it exists difference of color performance between different display apparatuses because of the native color gamuts of themselves. Therefore, the color gamut of the display apparatus has to be adjusted or corrected in order to match the standard color gamut of HDTV or Rec. 709. For example, the color gamut of the display apparatus is adjusted to the triangular region surrounded by the points 301, 302 and 303. When the color coordinates of the points 301, 302 and 303 in CIE x, y color space are respectively adjusted to (0.64, 0.33), (0.30, 0.60) and (0.15, 0.06), the points 301, 302 and 303 are represent the red light, the green light and the blue light, and the display color gamut of the display apparatus is matched with the standard color gamut of HDTV or Rec. 709. As a result, the different display apparatuses may be color-adjusted or color-corrected so as to have the same color performance corresponding to HDTV.
Moreover, besides the three primary colors (i.e. red, green and blue), the three secondary colors (i.e. yellow, cyan and purple) and the white color are also displayed by the display apparatus by way of combining the three primary colors. For example, the yellow color is displayed or generated by combining the red light and the green light, the cyan color is displayed or generated by combining the green light and the blue light, the purple color is displayed or generated by combining the blue light and the red light, and the white color is displayed or generated by combining the red light, the green light and the blue light. The coordinates of the yellow color, the cyan color and the purple color (i.e. the three secondary colors) are respectively drawn as the points 304, 305 and 306, and the coordinate of the white color is drawn as the point 307.
Please refer to FIGS. 1 and 2. FIG. 2 schematically illustrates the adjusted color gamut of a conventional display apparatus of prior art. The coordinates corresponding to the three secondary colors and the white color are adjusted in CIE x, y color space in order to adjust, enhance or improve the color performances of the three secondary colors and the white color, so that the color performance of the display apparatus is adjusted to become warmer or colder. For example, the point 304, which is corresponding to the yellow color displayed by the display apparatus, can be adjusted toward the point 302 (i.e. the green color) and finally shifted to the point 304′. Similarly, the point 305 corresponding to the cyan color and the point 306 corresponding to the purple color can be adjusted toward the point 303 (i.e. the blue color) and finally shifted to the point 305′ and the point 306′. The point 307 corresponding to the white color is adjusted and shifted to the point 307′ because of the above adjustment. Consequently, the color performance can be adjusted in the standard color gamut of HDTV in order to match the user demands and situations.
The native color gamut of the display apparatus can be adjusted to the required color gamut and the details of the color performance can be corrected by the above-mentioned adjustment. However, the adjusting method mentioned above is implemented by way of adjusting the color coordinates in CIE x, y color space with a colorimeter. It is well known that the color coordinates of the three primary colors in the native color gamut of the display apparatus are captured and measured by the colorimeter. Because the color coordinates are absolute coordinate value in CIE x, y color space, the color coordinates are not intuitive for users to recognize and memorize and the colors corresponding to the coordinates and the changes during the adjustment are not simple to imagine. Therefore, the appropriate amount of change of the color coordinate is always found by way of trial and error when adjusting the conventional display apparatus. It is difficult for users to adjust or correct the color performance of the display apparatus without the colorimeter.
There is a need of providing an adjusting method and a display apparatus using the same to obviate the drawbacks encountered from the prior art.